Online retail giant Amazon says it knows its customers so well it can start shipping even before orders are placed.

The Seattle-based company, which late last year said it wants to use drones to speed package delivery, gained a patent last month for what it calls "anticipatory shipping''.

Amazon, the Journal reported, says it may box and ship products that it expects customers in a specific area will want, based on previous orders and other factors it learns from its customers' shopping patterns, even before they place an online order.